title: The protective effect of sodium nitroprusside (SNP) treatment on Arabidopsis thaliana seedlings exposed to toxic level of Pb is not linked to avoidance of Pb uptake.
abstract: The effects of 100 μM Pb(NO₃)₂ on 7-day-old Arabidopsis thaliana seedlings grown from seeds pretreated with a nitric oxide donor, sodium nitroprusside (SNP), or a nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) were investigated. Physiological stress induced by Pb (reduced root growth) was less evident in seedlings grown from seeds pretreated with SNP. However, SNP pretreatment of seeds did not affect Pb accumulation in the seedlings. Pb exposure caused oxidative stress by elevating hydrogen peroxide (H₂O₂) and lipid hydroperoxide contents of the seedlings. SNP pretreatment of seeds counteracted Pb toxicity by reducing the H₂O₂ and lipid hydroperoxide contents of Pb-exposed seedlings. Additionally, Pb-induced rises in antioxidative enzyme activities were reversed by SNP pretreatment of seeds. It was concluded that the ameliorating effects of SNP pretreatment were associated with the release of nitric oxide because cPTIO reversed these effects of SNP pretreatment of seeds and more importantly SNP pretreatment did not trigger an avoidance mechanism.
authors.affiliation: School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
authors.forename: Ing Chia
authors.initials: IC
authors.lastname: Phang
authors.forename: David W M
authors.initials: DW
authors.lastname: Leung
authors.forename: H Harry
authors.initials: HH
authors.lastname: Taylor
authors.forename: David J
authors.initials: DJ
authors.lastname: Burritt
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D017360:Arabidopsis / Q000187:drug effects* / Q000378:metabolism; D001565:Benzoates / Q000494:pharmacology; D001673:Biodegradation, Environmental; D002374:Catalase / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D007854:Lead / Q000378:metabolism / Q000633:toxicity*; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism; D012639:Seeds / Q000187:drug effects / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001565:Benzoates; D007093:Imidazoles; D020030:Nitric Oxide Donors; D017382:Reactive Oxygen Species; D012989:Soil Pollutants; C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; D009599:Nitroprusside; D007854:Lead; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase